Skip to main content

C is Not a Subset of C++

I came across an absurd article.

A well-written C program is a C++ program. Therefore, a well-written C program should be compilable with a C++ compiler.

This statement was undoubtedly true before 1999. Bjarne Stroustrup definitely took C compatibility into account when creating C++. At that time, well-written C code that adhered to the ANSI C standard was correctly compiled with a C++ compiler. However, that's limited to the time before the release of C99.

C99 introduced various new features, which C++ had already implemented differently or did not consider necessary. Moreover, the release of the new C11 standard and the new C++ standards(C++03, C++11, and more) have widened the gap between the two languages to a point where it is practically impossible to bridge.

Code that follows the C89 standard can still be compiled with a C++ compiler. But how many programs nowadays use C89? Try to find an actively developed project that uses C89. I have never tried to find one.

So, people who make such statements these days simply have not studied the topic properly. They might have learned it 20 years ago. When I told one such person that C++ and C specs have changed since C99 and that well-written C code that adheres to the C99 standard may not be compiled with a C++ compiler, the response I received was even more ridiculous.

The problem is not the standard; a well-written C program should be compilable with a C++ compiler. If the code cannot be compiled with a C++ compiler, it is not well-written C code.

Ah... it is truly shocking and absurd. He is misguided and overlooks the inherent differences between the two languages.

I cannot understand why one would look to C++ to define what well-written C code is. The two languages have already diverged. There was a time when Bjarne Stroustrup tried to merge C and C++, but he gave up on that idea. He even says that C/C++ is a term used by people who don't have a clue about programming. You should not use C/C++ to refer to C and C++, as they are no longer the same language. If you claim that only code that can be compiled with a C++ compiler is well-written C code, you are essentially giving up on all the features added to C since C99.

Let me clarify: well-written C code that adheres to the standard will not be compilable with a C++ compiler.

This article is a translation of a Korean post written in 2015. If you would like to view the original, please refer to this link.

Translating and revisiting it after 8 years, I feel a little better seeing that the term "C/C++" is used more infrequently than in the past since the establishment of modern C++.

Labels:

Comments

Post a Comment

Popular posts from this blog

[C++] Handling Exceptions in Constructors

When you use RAII idiom, there are often situations where constructors have to do complex tasks. These complex tasks can sometimes fail, resulting in throwing exceptions. This raises a concern: Is it okay to throw exceptions in constructors? The first concern is memory leaks. Fortunately, memory leaks do not occur. Variables created on the stack are released through stack unwinding, and if an exception occurs during heap allocation with the new operator, the new operator automatically deallocates the memory and returns nullptr . The next concern is whether the destructor of the member variables will be called correctly. However, this is also not a problem. When an exception occurs, member variables can be divided into three categories: fully initialized member variables, member variables being initialized, and uninitialized member variables. Fully initialized member variables have had their constructors called and memory allocations completed successfully. In the example code, t
Post a Comment
Read more

Iterator Adapters in Rust

An Iterator that takes another iterator and returns a new one is called an iterator adapter . The name "adapter" comes from one of the GoF's design patterns, the adapter pattern . However, in reality, it corresponds more to the decorator pattern , so if you pay too much attention to the name, you might get confused about its purpose. So it's better not to worry too much about the name. Enough complaining about the name, what does an iterator adapter do? An iterator adapter adds a task to be performed when the iterator iterates. This will be easier to understand when you see an example. The map function is one of the famous adapters. The iterator returned by the map function for those who have used functional languages iterates over new values transformed from the original values. Besides, various adapters are already implemented in the standard library. Among them, the most frequently used are those that are convenient to use with loops. Examples include the
Post a Comment
Read more

What is the size of an empty object?

Consider a class like the one above. Commonly called an "empty class," this class has no internal variables. So, how big is this empty class? At first glance, the size should be 0 since there are no member variables. However, the size is never 0 in any language, whether Java, C#, C (in this case, a struct), or C++. This is to ensure that two different objects never have the same address. Empty classes typically have a size of 1 byte in a 32-bit environment and 2 bytes in a 64-bit environment. However, the exact size cannot be determined. According to the specification, the size just needs to be non-zero. The precise size depends on the implementation. This is a translation of my old Korean post written in 2015. Because the size can vary depending on the implementation, it is now possible to have different sizes (although still not 0). And Languages like Rust have even introduced zero-sized types . We will look at this topic in more detail at a future opportunity.
Post a Comment
Read more